i 9 4 



CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Equations of Condition. 

 A = D — zx. 



To reduce the number of equations, those nearly alike 

 were combined, as follows: Equations No. 1, 6, 7 and 21; 

 2, 3 and 14; 4 and 8; 5, 10 and 11; 9, 12 and 20; 13, 22 

 and 23; 15 and 16; 17, 27 and 28; 18 and 19; 24, 25, 26 

 and 30; and 29 and 31, giving the 11 equations: — 



No. 



1 



2 



3 

 4 

 5 

 6 



7 

 8 



9 

 10 

 11 



a 

 D 



